The present disclosure relates generally to well drilling operations and, more particularly, to a methods and systems for monitoring a wellbore using an interferometer.
During an oil recovery operation, water injection is often used to aid in recovery of production fluids. However, implementation of a waterflood program may result in injector-producer linkages, uncontrolled hydrofracture growth, water breakthrough in thief layers, or other issues resulting from water injection supported production. These conditions may result in the loss of hydrocarbon production and/or production of large volumes of water. Monitoring the waterflood injection can help solve these problems.
Various types of interferometers have been used to locate and/or detect longitudinal positions of time-varying disturbances in a non-central location within the sensing loop. The Sagnac interferometer is one of the general arrangements of interferometers that has been used to detect mechanical or thermal disturbances or vibrations. The Sagnac interferometer operates by generating a light signal with a predetermined wavelength, transmitting the light signal through an optical fiber loop, and detecting the resulting coherent light phase shift. The characteristics of the coherent light phase shift is known in the art to provide information regarding physical disturbances or vibrations located within the loop of the Sagnac interferometer.
High Data Rate Telemetry used in drilling wellbores requires high efficiency of pressure pulse detection and requires high bit rate transmission. However, standard electromechanical gages cannot meet this technical data requirement. A Sagnac interferometer could be used for pressure pulse detection. However, the reference loop module of the interferometer must be isolated from environmental noise and vibration. Vibration dampening fillers and various signal filtering techniques have been used to limit the effect of these interfering factors with various degrees of effectiveness.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.